An MBMS (multimedia broadcast multicast service) mechanism which is introduced into an LTE (Long Term Evolution) system, is also referred to as an eMBMS (evolved MBMS) mechanism. Control information of an MBMS is transmitted on an MCCH (multicast control channel), and MCS (modulation and coding scheme) information of the MCCH is transmitted on a BCCH (broadcast control channel).
Related logical channels of the MBMS include: a BCCH, an MCCH, and an MTCH (MBMS point-to-multipoint Control Channel). The BCCH is configured to broadcast, by a network, system information to UE (user equipment). The MCCH is configured to transmit, by the network, MBMS-related control information to the UE. One MCCH may correspond to one or more MTCHs. Only UE that can read an MBMS service can use the MCCH. A base station notifies, by means of a system broadcast, the UE of an MCS of the MCCH and period information of the MCCH (the period information of the MCCH includes a modification period (MP) and a repetition period (RP)). The MTCH is a point-to-multipoint downlink channel, and is configured to transmit, by the network, MBMS service data to the UE. Only UE that can read an MBMS service can use the MTCH. Information about the MTCH is indicated by an MCCH corresponding to the MTCH. The network indicates the MCCH to the UE by using the BCCH, and then indicates the MTCH to the UE by using the MCCH, so that the UE reads an MBMS service carried on the MTCH.
At present, in an MBMS system, an MCCH message can be sent only by using an MBSFN (multimedia broadcast multicast service single frequency network) subframe. The MBSFN subframe is a dedicated subframe and can be used to send only one data block. UE can obtain the MCCH message by reading the MBSFN subframe at a corresponding time point. The MBSFN subframe can be used to transmit only one data block, and one data block can be used to transmit the MCCH message or transmit other data than the MCCH message. However, if the MCCH message cannot fully occupy all resources in the MBSFN subframe, other data cannot be sent in the MBSFN subframe either, resulting in resource waste.